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Maximum size : 10 cm

Assam Danio - Devario assamensis : Complete Fish Profile & Care Guide

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The Assam Danio (Devario assamensis) is a stunning addition to any peaceful community aquarium. These active and friendly fish bring a lively presence to your aquatic ensemble, particularly if you already have larger species in your collection. However, it's important to note that Assam Danios are among the larger Danio species and require a spacious aquarium with ample room for swimming.

These Danios prefer cooler temperatures and are relatively adaptable when it comes to water parameters, making them suitable for both experienced and beginner aquarists as long as they provide a sufficiently large tank. In their natural habitat, Assam Danios are known as shoaling species, so maintaining them in groups of six or more individuals is highly recommended. Not only does this dynamic group help mitigate aggression towards other tank inhabitants, as the fish focus on establishing their hierarchical rank within the group, but it also enhances the vibrant colouration of the males in the presence of rival males.

When selecting tankmates for the Assam Danios, consider medium to large-sized Danios, Characins, Barbs, Rasboras, peaceful Cichlids, Catfish, and Loaches. It's advisable to avoid smaller species that may be perceived as snacks or slow-moving species that could feel uneasy around these energetic fish.

Creating an ideal aquarium setup for the Assam Danios involves replicating the ambience of a flowing river or stream. Smooth rocks or boulders can be used as a substrate, complemented by fine gravel or sand. Enhance the environment with driftwood roots or branches, and introduce hardy aquatic plants like Bolbitis, Anubias, or Microsorum. Adequate oxygenation and a reasonable flow rate are crucial, as these fish enjoy swimming against the current. Consider incorporating a powerhead or an internal filter to achieve this effect.

Due to their natural habitat in pristine environments, Assam Danios are intolerant to excessive organic waste accumulation. Therefore, maintaining excellent water conditions is essential for their well-being. It is crucial never to introduce them into an immature aquarium without a stable biological balance. Additionally, as accomplished jumpers, a secure and tight-fitting lid is necessary to prevent any unexpected escapades.

The Assam Danio exhibits an exquisite colouration, with a yellowish-green body and a white abdomen. Two wide longitudinal reddish-orange stripes grace their upper region above the lateral line, accompanied by broken orangy-red stripes along their sides. Noteworthy features include large mouths and eyes, a forked caudal fin, transparent pectoral, pelvic, and anal fins, a reddish caudal fin, and a pinkish dorsal fin.

Assam Danio Photos

Sexual Dimorphism

Differentiating between male and female Assam Danios can pose some challenges due to their subtle physical differences. However, keen observation allows for identification. Generally, females exhibit a slightly larger size compared to males, noticeable through their more rounded abdomen. Moreover, their colouration tends to be comparatively duller in appearance.

In contrast, males typically possess a smaller and slimmer physique, showcasing more vibrant colours than their female counterparts. Their vivid hues contribute to an eye-catching appearance that distinguishes them within the species.

Quick Facts

Scientific NameDevario assamensis
Year Described1984
Other NamesAssamese Danio
Max Size10 cm
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 6+
LifespanUp to 8 Years

Water Parameters

Water TypeFreshwater
PH6.0 - 8.0
GH5 - 15
TDS36 - 215
59 - 71
15 - 21

Natural habitat

Assam Danios are native to the beautiful waterways of South Asia, specifically the tributaries of Lake Mirik and the Mahananda River in West Bengal, as well as the Kalmoni River drainage in Assam. These remarkable fish can also be found in India's lower Brahmaputra River System.

Thriving in various environments, Assam Danios inhabit both lowland and higher-altitude regions. They prefer moderately flowing, clear, well-oxygenated waters, making pools, streams, and rivers their preferred habitats. Within these aquatic realms, gravel and rocks provide the substrate, while overhanging vegetation and marginal plants add a touch of natural beauty.

These agile fish navigate their habitat gracefully and are a sight to behold as they interact with their surroundings. From seeking shelter to engaging in natural behaviours, Assam Danios truly bring life to the captivating ecosystems they call home.

How to breed the Assam Danio

Assam Danios, as egg-scatterers, display no parental care towards their offspring. Under favourable conditions, these Danios will often engage in spawning behaviours, and in a densely-planted and well-established aquarium, a small number of fry may naturally emerge without intervention. However, if you desire to enhance the quantity of fry, a more controlled approach is necessary.

To begin, conditioning your adult group together is advisable. However, setting up a separate breeding tank becomes crucial for successful breeding. The breeding tank should be filled halfway with mature water, and ample space should be dedicated to suitable spawning mediums such as java moss, spawning mops, or the placement of mesh, pebbles, or marbles on the tank's base to provide hiding spots for the eggs. Maintaining slightly acidic to neutral water conditions with a slightly elevated temperature is recommended. Additionally, the inclusion of an air stone or air-powered sponge filter will facilitate water movement and oxygenation.

Once the adult fish are adequately conditioned, and the female's abdomen is visibly swollen with eggs, introduce one or two pairs into the breeding tank. Stimulate spawning by offering small amounts of live and frozen food. Multiple spawning events are likely to occur before the female has exhausted her egg supply. Spawning typically transpires within 24 hours, and once the female appears slimmer, indicating that all eggs have been laid, it is advisable to remove the adults from the tank after 48 hours to prevent them from consuming the eggs.

The incubation period for the eggs can vary based on temperature but generally spans between 24 and 36 hours before the fry hatch. After a few days, the fry will begin swimming freely. Initially, nourish the fry with liquid fry food, Paramecium, or powdered food. Then, as they grow, introduce newly hatched brine shrimp and microworms after approximately a week, once they have reached a size suitable for consuming these food sources.

Diet & feeding

Assam Danios exhibit an adaptable feeding behaviour within the aquarium environment. While they are not overly selective eaters, offering them a high-quality dried food product is essential as the primary component of their diet. To ensure optimal nutrition and overall health, complement their meals with regular servings of frozen, live, and freeze-dried foods.

Consider incorporating a diverse range of food options, such as cyclops, mosquito larvae, chopped earthworms, brine shrimp, daphnia, and bloodworms. This varied diet contributes to preserving the vibrant colours and overall well-being of your Danios. Additionally, occasional supplementation of vegetable flakes will provide a well-balanced nutritional profile, further enhancing their dietary requirements.

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